A jump in an Arrhenius plot can be the consequence of a phase transition

FEBS Letters

Travers, F.¹  Barman, T.E.¹  Biosca, J.A.¹ 

[1] INSERM U 128, B.P. 5051, 34033 Montpellier Cedex, France

关键词: Arrhenius plots;    discontinuous;    Phase transition;    Myosin subfragment 1;    ATP binding to;    Conformational change;    Enzyme kinetics;   

DOI  :  10.1016/0014-5793(83)80151-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The temperature dependence of the kinetics of the binding of ATP to myosin subfragment−1 was studied by an ATP chase technique in a rapid−flow—quench apparatus: A temperature range of 30°C to −15°C was obtained with ethylene glycol as antifreeze. The Arrhenius plot of k ₂ is discontinuous with a jump at 12°C. Above the jump ΔH ^≠ = 9.5 kcal/mol, below ΔH ^≠ = 28.5 kcal/mol. Few such Arrhenius plots are recorded in the literature but they are predicted from theory. Thus, we explain our results as a phase change of the subfragment 1−ATP system at 12°C. This is in agreement with certain structural studies.

【 授权许可】

Unknown